Thread protector



March 17, 1936. J s M 2,034,423

THREAD PROTECTOR Filed Nov. 29, 1935 INYENTOR Patented Mar. 17, 1936 NITED STATES THREAD PROTECTOR Y Peter J. Shrum, Monaca, Pa assignor to Pittsburgh Screw and Bolt Corporation, a corporation of Pennsylvania Application November '29, 1935, Serial No. 52,124

13 Claims.

Thisinvention relates to devices for protecting the threaded ends of articles such as tubes, pipes, tool joints, etc.

Devices utilized for this purpose are commonly known as thread protectors and their purpose is not only to protect the threads which are cut or otherwise formed on the ends of such articles, but to stifien the ends of such articles especially when the same are hollow articles as tubes and pipes.

Thread protectors, in order to be efiicient, must be capable of being readily applied to the article to be protected; capable of being securely held in protecting position without galling the threads to be protected; capable of easy removal when de sired; relatively cheap to manufacture and rugged so as not to be easily distorted.

An object of this invention is to produce a thread protector which, while relatively simple and relatively cheap to manufacture, is nevertheless extremely efiective in giving protection to the threaded end of a pipe, tube or other threaded article and which when tightly screwed to protecting position remains locked in such position until removal of the same is desired.

Another object of this invention is to produce a thread protector which can be screwed tightly on any threaded article for which it is designed, even though standard tolerances have not been adhered to in forming the threads to be protected.

Another object is to produce a thread protector which will not become loose during shipment of the article to which the protector is applied.

A further object is to produce a protector which will not only protect the threads to which it is applied, but will serve as a cushion for the protected portion of the article.

A further object is to produce a-thread protector which requires no accurate machine work as is required in many of the protectors disclosed in the patented art and in some or the protectors being manufactured today. I

A still further object is to produce a rugged protector capable of being manufactured in various sizes and which is self adjusting for a relatively wide variation from standard in the threads Figure 1 is a view in sectional elevation of a thread protector embodying this invention.

Fig. 2 is a view in sectional elevation of the thread protector shown in Fig. 1, but in this view, the protector is shown in place on the end of a pipe or tube and the protector itself is taken from the position shown in Fig. 1.

Fig. 3 is aviewsimilar to Fig. 2, but in this view the protector has been screwed on the pipe or tube until it is locked in protecting position. 10

A thread protector embodying this invention comprises a relatively thin walled body adapted to enclose the externally threaded end. of a pipe, tube or other article to be protected, a thread engaging split ring mounted within and slidable 1 longitudinally of the body and means for preventing or limiting relative rotary movement be-' tween said ring and said body.

The body of the protector is provided with an open end which is the entrance end. The other 20 end may be either open or closed; if open, the body at that end will preferably be turned inwardly to form an annular stop flange.

When the protector is in protecting position on the threaded end of a pipe, tube, or other 25 threaded article, the closed end of the body or stop flange as the case may be is adapted to be tightly pressed against the end of the article to be protected.

A portion of the walls of the protector body converges toward its open end. The split ring is adapted to make threaded engagement with the threads of the article to be protected.

Whenin'stalling the protector on the end of a tube, pipe or other article, the split ring is 35 forced by the end of the article into contact with the stop flange, if the protector has both ends open or the closed end, if the protector has one end closed. When, the protector is now rotated, the threads of the split ring engage the threads 40 of the article to be protected. Rotation of the protector is continued until it becomes tightly locked in place. Locking takes place because rotation of the protector after the end of the pipe or tube contacts with the stop flange or closed 5- end, causes the split ring (which is prevented. from rotating relative to the body) to travel or slide longitudinally of the body toward the entrance end of the protector and between its inwardly converging walls and the threaded por- 50 tion of the tube or pipe.

The particular embodiment illustrated in the drawing comprises a sleeve-like body or shell 4 which is open at one end and closed at the other. Adjacent its closed end the body is bulged out- 55 nected by walls that converge toward the em wardly as shown at 5 so as to stiffen the same. Between this bulged portion and the open end which I term the entrance end, the body has 'two cylindrical portions; one portion 6, immediately adjacent the bulged portionand one portion 1 of smaller internal diameter which forms the entrance end of the protector. These two portions 6 and 1 are joined by a portion 8 resembling a hollow truncated cone. Thus the two cylindrical portions of different diameter are contrance end of the protector.

An internally threaded split ring 9 formed of relatively soft material is located within and,

slidable longitudinally of the body portion and normally occupies a position adjacent the closed end or the stop flange. The larger of the cylindrical portions of the body, the part 6 which extends frcm a. to b. is indented so as to provide an inwardly extending projection ID of such shape as to be capable of occupying a position between the separated ends Ii and I? of the split-ring protector is applied.

I the converging portion 8 and toward the entrance end it will be contracted and tightly wedged into the decreasing space between the converging walls of the body and'the article to which the The cylindrical portion of smaller diameter.

that is the portion extending from point c to the words, the wallsof the body may be tapered from entrance end d may be omitted if desired in protectors designed for certain purposes. In other point b to the entrance end d. If properly designed this will allow the splitring to move outwardly to the entrance end d. Ordinarily, it is preferable to have the walls at the entrance end as shown in the drawing, in other words. as part of ahollow cylinder which snugly fits the pipe,

tube or other threaded article to be protected as this facilitates the placing of the protector onto the article to be. protecte I The split ring may be formed from various materials such as fiber, one of the phenolic condensation products, lead, belting and in some cases, steel or another relatively hard metal. In most cases, however, it is preferable to use a relatively soft material since such material serves thereof, including the more or less as a cushion for the threadsto be protected. When using material in which threads may be formed as by rolling or casting, it is preferable to provide the ring with threads and it is preferable to have the pitch of the threads approach as nearly as possible the pitch of the threads to be protected. In some cases where a relatively soft material is used. and where the threads to be protected can make threaded engagement with the unthreaded ring the threads may be omitted. In other threaded ring may be used.

' In most cases it will be found desirable. when using a protector, to smear the inner surfaces ring, with a relatively heavy grease. This will serve to keep out moisture, to .seal the joint between the entrance end of the protector and the member being protected and will prevent the threads from rusting.

words a plain un- In some cases it may be found desirable'to have both ends of the protector open especially when the body portion is formed from a section of tubing. In such case the body will be turned in in the nature of an annular lip or flange e, ,f, to form a stop for the end of the article or member to be protected.

This invention may be embodied in internal protectors as well as in external protectors such as shown in the drawing. Internal protectors are used for internally threaded pipe and for protecting the internal threads o1 nipples'used in connecting sections of pipe or tubin The clearance between the sides of fihe inwardly projecting member I 0 and the ends II and I2 ofv the thread engaging ring must be such as will permit the ring to be contracted sumciently to move lengthwise of the protector into locking position on the article or member being protected.

It will be obvious that the body of the protectors may be made from sheet metal such as sheet steel or proper gauge or in the case of protectors having both ends open, from suitable metal tubing,

either welded or seamless. In some cases it may be preferable to die cast the body of the protector. Having thus described my invention, what I claim as newand desire-to secure by Letters Patent is:

1. A thread protector comprising a thread engaging element, a support on which such element .30 is mounted for longitudinal movement, means for limiting rotational displacement of said element with relation to said support and means'for' limiting longitudinal movement ofsaid support with relation to the member the threads of which are to be protected.

2. A thread thread engaging element, an annular support on which such element is mounted for longitudinal movement, means for limiting relative rotational movement between said support and said element and means for limiting longitudinal movement of said support with relation to the member the threads of which are to be protected.

3. A thread protector comprising a thread engaging element in the form of a split ring,.an annular support within which such element is mounted for longitudinal movement, means for limiting rotational movement of said element with relation to said support and means for limiting longitudinal movement of said support with relation to the member the threads of which are to be protected.

4. In a thread protector, a ring-like thread engaging element, an annular support within which such element is mounted for longitudinal sliding movement, means for preventing relative rotational movement between such element and ,said support and means serving as a stop for limiting longitudinal movement of said support with relation to the threaded member to be protected whereby rotation of said support during threaded engagement of the thread engaging element said element is caused to travel longitudinally of said suppo 5. A thread protector comprising a thread en-. gaging element, a support on which said element is slidingly mounted and which is provided with a portion of frusto-conical form, means for limiting rotational displacement of said element with relation to said support and means for limiting longitudinal movement of said support with relation to the member the threads of which are to be protected.

6.A thread protector comprising a thread enprotector comprising a ring-like internal surface, means for limiting rotational displacement of said element with relation to said support and means for limiting longitudinal movement of said support with relation to the member the threads of which are to be protected whereby the thread engaging element is caused to travel longitudinally of the support into locking position between its frusto-conical surface and the threads to be protected. T

'1'. A thread protector comprising a thread engaging element, a rigid support on which such element is mounted for sliding movement and which throughout a portion of its length is inclined inwardly toward the longitudinal axes of the protector, means for limiting rotational displacement of said element with relation to said support and means for limiting longitudinal movement of said support with relation to the article, the threads of which are to be'protected whereby the thread engaging element is caused to travel;

. longitudinally of the support into locking posiengaging member located within andtion between its inclined portion and thethreads to be protected.

8. In a thread protector, a skirt-like member for surrounding the threads'to be protected and having portions of its inner surface inclined inwardly toward the entrance and ot-the ,protec tor, means at the other endforming astop for the end of the article having threads to be protected, a contractible ring-like member slidable within the body'mem'ber and which.is;;adapted to make threaded engagement with'the threads to be protected and means preventing rotation of said ring-like member with'relation to said skirt-like member.

9. In a thread protector, a skirt-like body member provided with one open and one closed end and having portions of its inner surface inclined inwardly toward its open end, a thread-- of relatively within an member with'relation to said body member.

10. In a thread protector, a skirt-like body member provided with one closed end and one open end and having portions of its inner surface inclined toward its open end, an internally threaded ring-like member located within and slidable toward and from the ends of the body member and means for preventing rotation of said ring-like member with relation to said body member.

11. In "a thread protector, a skirt-like body member thewalls of a portion ofwhich converge toward the entrance end of the protector, an internally threaded split ring located within and slidable towardfand from the ends of the body member and means for preventing rotation of said ring-like member with relation to said body member.

.12; Ina thread protector, a sleeve-like member clo'sdiatoneend and open at the other and tapers inwardly toward its open end, a split ring soft material mounted for sliding ilengthwise of the sleeve-like member andmeans located between the ends of said ring for preventing the same from rotating with rela- .tion to the sleeve-like member.

13.1 In a thread protector, a support, a thread engaging element mounted on said support, means for limiting relative rotational movement between said support and said thread-engaging element andmeans for limiting relative longitudinal movement between said support and thearticle to be protected; said thread-engaging element being mounted for movement longitudinally of said support whereby rotational movement of,

said-support 'with relation to saidarticle causes the thread-engaging element to move longitudinally of the support. I

. V PETER J SHRUM. 

